Sodium Bisulfite 40% ACS Grade

Product Overview

Sodium Bisulfite (NaHSO₃) is a white crystalline powder or colorless solution that serves as a versatile reducing agent and antioxidant in a range of chemical applications. This ACS Grade material is formulated for high purity and consistent performance in analytical chemistry and water treatment processes, where trace contaminants can impact reaction outcomes and measurement accuracy. The solution is typically supplied at 40% w/v, providing a reliable source of bisulfite for titration standards, dechlorination steps, and reductive chemistry. Product specifications emphasize controlled acidity, low color, and minimal impurities to meet stringent lab and industrial requirements.

The ACS Grade specification supports reproducible results across critical workflows, including sample preservation, permission-based analytical methods, and process streams where rapid sulfite-mediated redox shifts are required. The material is commonly utilized for analytical reagents, water treatment, and preservation roles in the food and photographic industries, among others. Properly stored and handled, it delivers dependable reducing capacity while maintaining compatibility with standard laboratory equipment and container materials.

Key Properties

• CAS: 7631-90-5
• Appearance: Colorless to pale yellow liquid
• Odor: Sulfide-like odor
• Solubility: Soluble in water
• Molecular Weight: 104.06 g/mol
• Molecular Formula: NaHSO₃
• Chemical Formula: NaHSO₃
• Specific Gravity (20°C): 1.23 (typical)
• pH (solution at 20°C): 5 (typical)
• Residue After Ignition: 0.05% (typical); ≤0.1% (max)
• Chloride: ≤0.2–0.5 ppm (typical 0.2 ppm; max 0.5 ppm)
• Nitrate/Nitrite (NO₃⁻): ≤1–2 ppm (typical 1 ppm; max 2 ppm)
• Ammonium (NH₄⁺): ≤0.5–1 ppm (typical 0.5 ppm; max 1 ppm)
• Sulfate (SO₄²⁻): ≤2–5 ppm (typical 2 ppm; max 5 ppm)
• Phosphate (PO₄³⁻): ≤2–5 ppm (typical 2 ppm; max 5 ppm)
• Arsenic (As): ≤0.02–0.1 ppm (typical 0.02 ppm; max 0.1 ppm)
• Heavy Metals (as Pb): ≤0.05–0.2 ppm (typical 0.05 ppm; max 0.2 ppm)
• Iron (Fe): ≤0.08–0.3 ppm (typical 0.08 ppm; max 0.3 ppm)
• Copper (Cu): ≤0.03–0.1 ppm (typical 0.03 ppm; max 0.1 ppm)
• Manganese (Mn): ≤0.05–0.2 ppm (typical 0.05 ppm; max 0.2 ppm)
• Nickel (Ni): ≤0.03–0.1 ppm (typical 0.03 ppm; max 0.1 ppm)
• Lead (Pb): ≤0.02–0.1 ppm (typical 0.02 ppm; max 0.1 ppm)
• Zinc (Zn): ≤0.3–1.0 ppm (typical 0.3 ppm; max 1.0 ppm)
• Aluminum (Al): ≤0.15–0.5 ppm (typical 0.15 ppm; max 0.5 ppm)
• Chromium (Cr): ≤0.03–0.1 ppm (typical 0.03 ppm; max 0.1 ppm)
• Cobalt (Co): ≤0.01–0.05 ppm (typical 0.01 ppm; max 0.05 ppm)
• Calcium (Ca): ≤2–5 ppm (typical 2 ppm; max 5 ppm)
• Magnesium (Mg): ≤1–3 ppm (typical 1 ppm; max 3 ppm)
• Potassium (K): ≤2–5 ppm (typical 2 ppm; max 5 ppm)
• Sodium (Na): ≤0.4–1 ppm (typical 0.4 ppm; max 1 ppm)
• Substances Reducing Permanganate: Passes test
• Sulfurous Acid (H₂SO₃) Content: ≤20–50 ppm (typical 20 ppm; max 50 ppm)
• Color (APHA/Hazen): ≤3–5 units (typical 3; max 5)
• Assay (wt %): 39–41% (typical 40%)
• Density (20°C): 1.20 g/mL
• Heavy Metals (as Pb) Note: ICP-OES; stringent quality standard compliance
• Standards Compliance: ACS Reagent Grade; USP-NF Monograph compliant

Common Applications

• Water Treatment: Reducing agent in dechlorination and oxidation control for drinking water and industrial process streams, helping to maintain residual disinfectant balance.
• Analytical Reagent: Used in various analytical chemistry procedures, including redox titrations and sample preservation, with tight impurity control to ensure accurate measurements.
• Food Preservation: Acts as an antioxidant and preservative in food processing to inhibit oxidation and extend shelf life when compatible with formulation requirements.
• Photography: Preservative in photographic developers, contributing to controlled reduction chemistry during image development.
• Chemical Synthesis: Intermediate and reagent in the synthesis of organic and inorganic compounds, supporting reductive transformations and reagent compatibility.

Safety Precautions

Handle Sodium Bisulfite under appropriate process controls, in a well-ventilated area, with compatible HDPE containers. Store away from light and moisture at cool conditions to minimize oxidation and degradation; protect from strong oxidizers and acids. Use PPE including chemical-resistant gloves, safety goggles, and a lab coat or equivalent protective wear. Ensure adequate ventilation and implement spill containment procedures in accordance with the SDS and local regulations.

In case of exposure, follow standard first-aid procedures: rinse eyes with water for several minutes and remove contact lenses if present; skin exposure requires removal of contaminated clothing and thorough washing with water. If inhaled, move to fresh air and seek medical attention if symptoms persist. For ingestion, rinse mouth and do not induce vomiting; seek medical attention immediately. Refer to the Safety Data Sheet for detailed instructions, including emergency response and transport information (UN 3265, Corrosive liquid, acidic, organic, Class 8, PG II).

Benefits

✔ High Purity ACS Grade – Ensures low impurity levels and consistent performance in analytical and process applications.
✔ Reliable Reducing Agent – Provides effective sulfite-based reduction with predictable behavior in redox systems.
✔ Controlled Impurity Profile – Low heavy metals and anions support compliance with strict regulatory and method requirements.
✔ Stable Storage Profile – Shelf life of up to 24 months when stored as recommended, reducing waste and rework.
✔ Standards Compliant – Meets ACS Reagent Grade and USP-NF Monograph expectations for dependable quality.